The term 'Bench Press Muscle' refers to two muscles that are used when performing a bench press exercise. The first muscle is the Pectoralis Major, commonly referred to as the PEC, which is a large chest muscle located in the upper chest. The second muscle is the Deltoid, commonly referred to as the DELT, which is a shoulder muscle located in the upper arm. Both of these muscles are important for stabilizing the body during a bench press exercise and are essential for proper form and technique.